tanawatpontchour/fotolia, Edited by Erin Kennedy
A gene that helps regulate sleep cycles may also be a factor in the spread of some types of breast cancer to other parts of the body. This was the conclusion reached by researchers at the National Cancer Institute in Bethesda, Maryland.
When breast cancer does not metastasize, or spread, to other parts of the body, approximately 99 percent of the women affected live at least five years after their cancer is diagnosed. But when breast cancer metastasizes to other organs, that survival rate drops to only 26 percent.(1)
Metastatic tumors are clusters of cancer cells that are located away from the organ where the cancer originated. These tumors are the cause of more than 90 percent of deaths associated with human cancer.(3)
Genes are the genetic code that instructs the cells in the body how to function. Circadian rhythm genes control how circadian rhythms function.
Circadian rhythms are natural cyclical changes in the body, functioning on an approximately 24-hour clock. Your circadian rhythm can be affected by outside factors such as light and dark cycles.
Circadian rhythms exert influence on when you sleep and wake up, on your body temperature, on when hormones are released, and many other facets of your life.(4)
One particular gene associated with circadian rhythm is called the Arntl2 gene. The NCI researchers discovered that variations in this gene appear to be associated with increased likelihood that breast cancer may spread to other organs.
Senior study author Kent Hunter, a researcher at the NCI said, “Our results suggest that there is a link between inherited factors that may influence how well circadian rhythms may be regulated and the probability that breast cancer will spread,”in an article by Reuters.
The NCI study began examining mice who had a particular type of breast cancer known as estrogen-receptor-negative breast cancer. It is harder to treat than some other types of breast cancer because it is less likely to respond to targeted hormone therapy.(1)